Backpack vacuum cleaner



FIG. 1 is a perspective view of a backpack vacuum cleaner showing my newdesign;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a left side elevational view thereof;

FIG. 4 is a rear elevational view thereof;

FIG. 5 is a right side elevational view thereof;

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a bottom view thereof.

CLAIM I claim the ornamental design for a backpack vacuum cleaner, asshown and described.